The diaphragm body in previously described force sensors is supported on the base body via one or more spacers so that a cavity is formed between the diaphragm body and the base body which is limited by one side of the diaphragm body and by one side of the base body. The volume of the cavity changes when a force acts on the diaphragm body. The surfaces of the base body and the diaphragm body limiting the cavity have a metal layer or coating, thereby forming electrodes opposite to each other of a precision capacitance meter having measuring capacitance. The cavity is filled with air as a dielectric medium for measuring.
The diaphragm body has a certain elastic flexibility and responds to a force acting thereon by bending. This changes the distance of the electrodes to each other and thereby the capacitance of the capacitor, which is defined by the cavity and the electrodes, respectively. Appropriate capacitive force sensors are often part of electronics. The base body is therefore known to be formed from a circuit board together with the associated electrode, as is described, for example, in U.S. Pat. No. 5,134,886. A disadvantage of these force sensors is that the cavity that is provided for bending under action of force also defines the measuring capacitance. Mechanical and electrical measuring properties therefore mutually influence each other. This is disadvantageous in both the mechanical and electrical configuration of a capacitive force sensor.